Overview

Teaching: 15 min
Exercises: 10 min

Questions

• What are the three different styles of LaTeX command?

Objectives

• Understand how LaTeX commands are structured

• See the difference between commands that take no arguments, one’s which take an argument and one’s which use a begin and end command.

LaTeX Commands

Commands with no arguments

As you’ve seen from the simple Hello World example, LaTeX commands all start with a ‘' character. We saw three types of examples on the previous page. The simplest was just a slash followed by a command, which was the maketitle command. This command takes some of the information that was already given and displays the title block.

\maketitle

LaTeX has a number of other commands like this, one of the most useful is \newpage which will insert a new page into the document. Lets modify our old document to have an extra page using this command:

\documentclass{article}
\begin{document}
\title{Hello World}
\author{Jane Doe}
\maketitle
\newpage
\end{document}

But when we build this document it still doesn’t have a second page, because LaTeX has decided since there’s no content after the \newpage command it won’t include the page. Lets add some extra text after the \newpage. Now the text ‘hello world’ will appear on the second page (and if we remove the \newpage it will appear on the first page.

\documentclass{article}
\begin{document}
\title{Hello World}
\author{Jane Doe}
\maketitle
\newpage
Hello World
\end{document}

Commands with arguments

Some commands in LaTeX take an argument or some extra information. This is done by writing a { and } symbol after the command and entering the arguments between them. We already saw this in the documentclass, author and title commands. Another useful command that works in this style is the \textbf command. This makes the text that appears between the { and } symbols into bold text. Lets try making the Hello World text we just wrote in bold.

\documentclass{article}
\begin{document}
\title{Hello World}
\author{Jane Doe}
\maketitle
\newpage
\textbf{Hello World}
\end{document}

Environments

Our third type of commands are called environments. They use a \begin and \end statement and span multiple lines, everything in between the begin and end statement is part of the environment. We saw this already with the \begin{document} and \end{document} commands, the content of our entire document should be between these. These state that everything between the begin and end commands are part of the document. Another environment we can use in this way is the abstract environment which uses the \begin{abstract} command, the text for our abstract is then placed between the \begin{abstract} and the \end{abstract}. We can place this anywhere in the code that we like, but we probably want it to appear just after the title and on its own page, so lets take the code we just wrote and add the abstract after the newpage and before the bold hello world. Note that the abstract environment is nested inside the document environment.

\documentclass{article}
\begin{document}
\title{Hello World}
\author{Jane Doe}
\maketitle
\newpage
\begin{abstract}
The text for my abstract..
\end{abstract}
\textbf{Hello World}
\end{document}

This now puts the abstract and the bold Hello World on the same page, perhaps this isn’t quite what we want so lets add another page between them:

\documentclass{article}
\begin{document}
\title{Hello World}
\author{Jane Doe}
\maketitle
\newpage
\begin{abstract}
The text for my abstract..
\end{abstract}
\newpage
\textbf{Hello World}
\end{document}

Using the \bigskip command

The command \bigskip creates a big empty section between two bits of text. Add a \bigskip to this document, after the abstract ends but before the document text.

\documentclass{article}
\begin{document}
\title{Hello World}
\author{Jane Doe}
\maketitle
\newpage
\begin{abstract}
The text for my abstract..
\end{abstract}
The document text
\end{document}

Solution

\documentclass{article}
\begin{document}
\title{Hello World}
\author{Jane Doe}
\maketitle
\newpage
\begin{abstract}
The text for my abstract..
\end{abstract}
\bigskip
The document text
\end{document}

Using the \textit command

The \textit command makes the text contained between its { and } characters into italics. Try using this command to make some italic text in your document.

Solution

\documentclass{article}
\begin{document}
\title{Hello World}
\author{Jane Doe}
\maketitle
\newpage
\begin{abstract}
The text for my abstract..
\end{abstract}
\textit{The document text}
\end{document}

Centering Text

The \begin{center} command will centre all text that follows it until a \end{center} command is issued. Try using this command to centre the text in your document.

Solution

\documentclass{article}
\begin{document}
\title{Hello World}
\author{Jane Doe}
\maketitle
\newpage
\begin{abstract}
The text for my abstract..
\end{abstract}
\begin{center}
The document text
\end{center}
\end{document}

Key Points

• LaTeX uses a series of commands all beginning with a \ character

• Some commands take additional arguments between a { and } character

• Some commands, known as environments lots of additional content between begin and end commands